diff --git a/.changeset/popper-virtualref-null.md b/.changeset/popper-virtualref-null.md
new file mode 100644
index 0000000000..f082fba769
--- /dev/null
+++ b/.changeset/popper-virtualref-null.md
@@ -0,0 +1,5 @@
+---
+"@radix-ui/react-popper": patch
+---
+
+Allow `PopperAnchor`'s `virtualRef` to accept a `RefObject<Measurable | null>`, matching the type that `useRef<Measurable>(null)` returns in React 19.
diff --git a/packages/react/popper/src/popper.tsx b/packages/react/popper/src/popper.tsx
index b396a9c94a..7602ed9381 100644
--- a/packages/react/popper/src/popper.tsx
+++ b/packages/react/popper/src/popper.tsx
@@ -76,7 +76,7 @@ const ANCHOR_NAME = 'PopperAnchor';
 type PopperAnchorElement = React.ComponentRef<typeof Primitive.div>;
 type PrimitiveDivProps = React.ComponentPropsWithoutRef<typeof Primitive.div>;
 interface PopperAnchorProps extends PrimitiveDivProps {
-  virtualRef?: React.RefObject<Measurable>;
+  virtualRef?: React.RefObject<Measurable | null>;
 }
 
 const PopperAnchor = React.forwardRef<PopperAnchorElement, PopperAnchorProps>(